Process of shaping metal surfaces and cleaning the same

ABSTRACT

In the process of shaping metal surfaces and cleaning the same which comprises shaping a hard metal surface in the presence of a cutting, grinding or forming oil based on mineral oil, subjecting said shaped metal surface having a residue of said cutting, grinding or forming oil thereon to the action of an aqueous cleaning solution and recovering said shaped metal surface free of said residue of said cutting, grinding or forming oil, the improvement which comprises (A) admixing said cutting, grinding or forming oil based on mineral oil, prior to said shaping step, with from 3% to 50% by weight of an oil-soluble, (a) Addition products of 2 to 5 mols of ethylene oxide to 1 mol of a fatty compound having a replaceable hydrogen atom and 12 to 18 carbon atoms selected from the group consisting of fatty acids, fatty amines and fatty alcohols, (b) Addition products of 5 to 6 mols of ethylene oxide to 1 mol of dodecylphenol, (c) Partial esters of sorbitol with fatty acids having 12 to 18 carbon atoms in a ratio of 1.5 to 3 mols of fatty acid to 1 mol of sorbitol, and (d) Mixtures thereof; and (B) utilizing as said aqueous cleaning solution, an aqueous composition containing from 0.05% to 0.5: of said oil-soluble, nonionic emulsifier.

United States Patent US. Cl. 29-1 4 Claims ABSTRACT OF THE DISCLOSURE In the process of shaping metal surfaces and cleaning the same which comprises shaping a hard metal surface in the presence of a cutting, grinding or forming oil based on mineral oil, subjecting said shaped metal surface hav ing a residue of said cutting, grinding or forming oil thereon to the action of an aqueous cleaning solution and recovering said shaped metal surface free of said residue of said cutting, grinding or forming oil, the improvement which comprises (A) admixing said cutting, grinding or forming oil based on mineral oil, prior to said shaping step, with from 3% to 50% by weight of an oil-soluble, nonionic emulsifier selected from the group consisting of:

(a) Addition products of 2 to 5 mols of ethylene oxide to 1 mol of a fatty compound having a replaceable hydrogen atom and 12 to 18 carbon atoms selected from the group consisting of fatty acids, fatty amines and fatty alcohols,

(b) Addition products of 5 to 6 mols of ethylene oxide to 1 mol of dodecylphenol,

(c) Partial esters of sorbitol with fatty acids having 12 to 18 carbon atoms in a ratio of 1.5 to 3 mols of fatty acid to 1 mol of sorbitol, and

(d) Mixtures thereof; and (B) utilizing as said aqueous cleaning solution, an aqueous composition containing from 0.05% to 0.5% of an anionic wetting agent and from 0.05 to 0.5% of said oil-soluble, nonionic emulsifier.

THE PRIOR ART In the shaping of hard metal surfaces by forging, diecasting, grinding, cutting and other processes, cutting, grinding or forming oils having a mineral oil base are frequently used, In cleaning the shaped pieces to which the said mineral-oil containing oils adhere, with the aid of aqueous solutions, a quick loosening of the mineral oils is indeed possible but the latter are generally not emulsified in the cleaning solution but separate out at the surface and cause a reoiling of the goods when they emerge from the solution. These difiiculties occur above all if the more volatile components of the mineral oil evaporate. The less volatile components can then practically no longer be removed from the surface of the shaped piece on rinsing because of their low solidification point.

OBJECTS OF THE INVENTION An object of the present invention is the development of a process of shaping hard metal surfaces in the presence of a cutting, grinding or forming oil based on mineral oil and cleaning the surfaces of the shaped metal from adhering oil in an aqueous cleaning bath while avoiding the deficiencies of the prior art.

Another object of the present invention is, in the process of shaping metal surfaces and cleaning the same which comprises shaping a hard metal surface in the presence of a cutting, grinding or forming oil based on mineral oil, subjecting said shaped metal surface having a residue "ice of said cutting, grinding or forming oil thereon to the action of an aqueous cleaning solution and recovering said shaped metal surface free of said residue of said cutting, grinding or forming oil, the improvement which comprises (A) admixing said cutting, grinding or forming oil based on mineral oil, prior to said shaping step, with fromv 3% to 50% by weight of an oil-soluble, nonionic emulsifier selected from the group consisting of:

-(a) Addition products of 2 to 5 mols of ethylene oxide to 1 mol of a fatty compound having a replaceable hydrogen atom and 12 to 18 carbon atoms selected from the group consisting of fatty acids, fatty amines and fatty alcohols,

(b) Addition products of 5 to 6 mols of ethylene oxide to 1 mol of dodecylphenol,

(c) Partial esters of sorbitol with fatty acids having 12 to 18 carbon atoms in a ratio of 1.5 to 3 mols of fatty acid to 1 mol of sorbitol, and

(d) Mixtures thereof; and (B) utilizing as said aqueous cleaning solution, an aqueous composition containing from 0.05% to 0.5% of an anionic wetting agent and from 0.05 to 0.5 of said oil-soluble, nonionic emulsifier.

A further object of the invention is the obtaining of a cutting, grinding or forming oil composition for use in the shaping of hard metal surfaces consisting essentially of a mineral oil containing from 3% to 50% by weight of an oil-soluble, nonionic emulsifier selected from the group consisting of:

(a) Addition products of 2 to 5 mols of ethylene oxide to 1 mol of a fatty compound having a replaceable hydrogen atom and 12 to 18 carbon atoms selected from the group consisting of fatty acids, fatty amines and fatty alcohols,

(b) Addition products of 5 to 6 mols of ethylene oxide to 1 mol of dodecylphenol,

(c) Partial esters of sorbitol with fatty acids having 12 to 18 carbon atoms in a ratio of 1.5 to 3 mols of fatty acid to 1 mol of sorbitol, and

(d) Mixtures thereof.

These and other objects of the present invention will become more apparent as the description thereof proceeds.

DESCRIPTION OF THE INVENTION It has new been found that the above objects can be achieved by utilization of the below-described process for shaping of hard metal surfaces by forging, die-casting, grinding, cutting and other processes with the aid of cutting, grinding or forming oils based on mineral oil whereby simultaneously or subsequently a shaping and then a cleaning with aqueous solutions takes place.

The novel process is characterized in that the metal surfaces are treated with cutting, grinding or forming oils which contain, singly or in a mixture, oil soluble, nonionic emulsifiers of the types:

(a) Addition products of 2 to 5 mols of ethylene oxide to 1 mol of fatty acids, fatty amines, or fatty alcohols with 12 to 18 carbon atoms each,

(h) Addition products of 5 to 6 mols of ethylene oxide to 1 mol of dodecylphenol.

(c) Fatty acid/sorbitol partial esters with a molar ratio of fatty acid to sorbitol of 1.5 to 3:1, the fatty acid having from 12 to 18 carbon atoms. The so-treated metal surfaces are then subjected in a known manner to the desired shaping, and then after-treated with an aqueous cleaning solution which contains an emulsifier of the same type as in the cutting, grinding or forming oil in amounts from 0.05 to 0.5% by weight as well as an anionic wetting agent in amounts of from 0.05% to 0.5% by weight.

The degree of ethoxylation of the fatty acids, fatty alcohols, fatty amines and dodecylphenol utilized lies therefore, within narrow limits. The designation of 2 to 5 or to 6 mols of ethylene oxide represent the statistical average value of the added ethylene oxide groups. Particularly good results are obtained if, as the oil-soluble emulsifier,

the addition product of 2 mols of ethylene oxide to 1 mol of oleyl alcohol is utilized.

According to a preferred method of the process, the identical oil-soluble, nonionic emulsifier is added both to the cutting, grinding or forming oil and to the cleaning solution.

The previously named oil-soluble, nonionic emulsifiers are added to the cutting, grinding or forming oils based on mineral oil in amounts of from 3% to 50% by weight, preferably from 5% to 25% by weight. Generally there are no difficulties with the mixing step. The product is a cutting, grinding or forming oil composition for use in the shaping of hard metal surfaces consisting essentially of a mineral oil containing from 3% to 50% by weight of an oil-soluble, nonionc emulsifier selected from the group consisting of:

(a) Addition products of 2 to 5 mols of ethylene oxide to 1 mol of a fatty compound having a replaceable hydrogen atom and 12 to 18 carbon atoms selected from the group consisting of fatty acids, fatty amines and fatty alcohols,

(b) Addition products of 5 to 6 mols of ethylene oxide to 1 mol of dodecylphenol,

(0) Partial esters of sorbitol with fatty acids having 12 to 18 carbon atoms in a ratio of 1.5 to 3 mols of fatty acid to 1 mol of sorbitol, and

(d) Mixtures thereof.

The metal surfaces are then shaped by forging, diecasting, grinding, cutting and other processes in a known manner.

After the shaping, the treatment of the shaped metal pieces with an aqueous cleaning solution takes place. This solution contains emulsifiers of the above described type as well as surface-active anionic wetting agents, such as, alkyl'benzenesulfonates, alkylsulfonates, olefinsulfonates, fatty acid methyltaurides etc. Particularly such compounds are suitable whose alkyl chains are straight or branched and contain 12 to 18 carbon atoms.

The cleaning solutions contain the nonionic oil-soluble emulsifiers in amounts of from 0.05% to 0.5% by weight and the anionic wetting agents in amounts of from 0.05% to 0.5 by weight. Higher concentrations can be used but no further improvement of the technical effect is hereby accomplished. The concentration data given are concentrations used in the application of the cleaning process. It has further proven advantageous to have the ratio of anionic wetting agents to the nonionic emulsifiers in the cleaning solution in the range of 4:1 to 1:3.

The aqueous cleaning solutions can be alkaline, neutral, or acidic, and they may contain the usual inorganic and organic ingredients. As inorganic ingredients are for instance suitable alkali metal hydroxides, alkali metal carbonates, alkali metal phosphates, alkali metal polyphosphates, alkali metal silicates, and alkali metal borates. The cleaning solutions can further contain known complexing agents, such as, gluconates, polyamino-polycarboxylic acids, hydroxyalkane-l,l-diphosphonic acids, and aminotrimethylene phosphonic acid either as free acids or alkali metal salts. Also suitable for inclusion in the cleaning solutions are corrosion inhibitors, such as lower molecular weight alkylamines and alkanolamines, and sodium nitrite. In some cases also fillers, such as, sodium sulfate and sodium chloride are added. In acidic cleaners the usual mineral acids are used, such as, hydrochloric acid, sulfuric acid, and phosphoric acid.

In the process, according to the invention, the metal surfaces, treated with the cutting, grinding or forming oils of the invention and shaped, are quickly and satisfactorily cleaned, and the loosened mineral oils firmly emulsified or clearly dissolved (solubilization). No separation of mineral oils on the surface occurs, and no re- 4 oiling of the treated metal pieces takes place, and thus the difficulties connected with this are avoided.

The following examples are illustrative of the practice of the invention without being deemed limitative in any respect.

All quantitative data in the following examples are in weight percent unless otherwise stated.

EXAMPLE 1 Aluminum sections were ground on a belt grinder with the aid of a mineral oil to which was admixed 10% of an addition product of 2 mols of ethylene oxide to 1 mol of oleyl alcohol as an oil-soluble, nonionic emulsifier. The aluminum sections thus treated were subsequently cleaned with an aqueous solution which contained 3% of sodium tetraboratel0H O 2% of tetrasodium pyrophosphate, 0.15% of dodecylbenzenesulfonate and 0.15% of an addition product of 5 mols of ethylene oxide to 1 mol of oleyl alcohol. The pieces were immersed in the cleaning bath for 2 minutes at 70 C.

The cleaning effect was satisfactory and the mineral oil which separated was emulsified in a stable emulsion. Even with an accumulation of 35 gm./l. of mineral oil in the cleaning solution no separation of mineral oil occurred.

EXAMPLE 2 Gears were prepared by machine cutting with the aid of a used oil to which was admixed 5% of an addition product of 2 mols of ethylene oxide to 1 mol of oleyl-amine. These pieces were subsequently treated with an aqueous cleaning solution which contained 3% of sodium sesquisilicate, 0.2% of a fatty alcohol sulfate (carbon chain length C -C and 0.15 of an addition product of 4 mols of ethylene oxide to 1 mol of a fatty alcohol (carbon chain length C C With immersion in the cleaning bath at C., a satisfactory cleaning was obtained in 3 minutes, and the separated oil was firmly emulsified in a stable emulsion.

EXAMPLE 3 Various steel parts which had been cold-formed with the aid of a mineral oil to which 20% of an addition product of 5 mols of ethylene oxide to 1 mol of dodecylphenol had been admixed, were treated with an aqueous cleaning solution which contained 10% of sulfuric acid and 0.5% of an alkylsulfonate (carbon chain length C -C as well as 0.1% of an addition product of 4 mols of ethylene oxide to 1 mol of stearyl alcohol. The pieces were cleaned for 5 minutes at 60 C. and degreased by immersion and were subsequently galvanized. The loosened mineral oil was homogenously and firmly emulsified so that no reoiling took place.

EXAMPLE 4 Machine parts prepared by forging and machine cutting with the aid of mineral oil with an admixture of 20% of an addition product of 5 mols of ethylene oxide to 1 mol of oleyl alcohol were subsequently cleaned with an aqueous solution which contained 0.l% of sodium nitrite, 0.3% of dodecylbenzenesulfonate and 0.2% of an addition product of 5 mols of ethylene oxide to 1 mol of oleyl alcohol. The pieces were immersed for 2 to 3 minutes at C. in the cleaning bath. The cleaning was satisfactory and there was no reoiling since the loosened mineral oil was emulsified in the form of a stable aqueous emulsion.

EXAMPLE 5 A larger number of nonionic, oil-soluble emulsifiers were examined in regard to their effectiveness for a stable emulsification or solubilization of mineral oil in aqueous cleaning solution in the following manner.

300 ml. of a solution containing 3% of borax-10H O and 2% of tetrasodium pyrophosphate were charged, always at 70 C, into a fatty-acid burette. To this solu tion were added 0.125% of dodecylbenzenesulfonate and 0.15% of the nonionic oil-soluble emulsifiers to be examined. Subsequently, a mixture of 1.5 gm. of pure paraffin oil With increasing amounts of the same nonionic, oil-soluble emulsifiers as in the already prepared solution was added to the cleaning solution. The mixture thus obtained was shaken by tilting the fatty-acid burette by 180 and subsequently the fatty-acid burette maintained at 70 C. in the thermostat. Such emulsions were considered as stable in which even after 2 hours no oily-phase separation on the surface had occurred.

The results of the examinations are summarized in the following table. In the left column the type of emulsifier is listed. For ethylene oxide addition products the number of added mols of ethylene oxide CEO) is always given in detail. In the right column the figures give the addition of the emulsifier in Weight percent where an emulsification or solubilization (clear solution) had been obtained.

From the table the superiority of the emulsifiers used in the invention procedure against very similar, other nonionic emulsifiers is clearly shown.

TABLE Required amount added to the mineral oil for emulsification or solubilization Olcic acid, 5 E

N0 emulsification.

Emulsifier Oleyl alcohol, 2 EO Oleic acid, 10 E0 Dodecylphenol, 4 E0 Dodecylphenol, 5 E0 Dodecylphenol, 6 E0 Dodecylphenol, 8 E0 Nonylphenol, 4 E O Nonylphenol, 5 EO Nonylphenol, 7 E0 Oleic acid-sorbitol ester (1.5 mols of olcic acid/mol of sorbitol). Olcic acid-sorbitol ester (3 mols of oleic acid/mol of sorbitol).

20%. 30% (50% fully solubilizcd). No emulsification.

The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood however, that other expedients known to those skilled in the art may be employed without departing from the spirit of the invention or the scope of the appended claims.

We claim:

1. In a process of shaping metal surfaces and cleaning the same which comprises shaping a hard metal surface in the presence of a cutting, grinding or forming oil based on mineral oil, subjecting said shaped metal surface having a residue of said cutting, grinding or forming oil thereon to the action of an aqueous cleaning solution and recovering said shaped metal surface free of saidresidue of said cutting, grinding or forming oil, the improvement which comprises 6 (A) admixing said cutting, grinding or forming oil based on mineral oil, prior to said shaping step, with from 3% to 50% by Weight of an oil-soluble, nonionic emulsifier selected from the group consisting of 5 (a) addition products of 2 to 5 mols of ethylene oxide to 1 mol of a fatty compound having a replaceable hydrogen atom and 12 to 18 carbon atoms selected from the group consisting of fatty acids, fatty amines and fatty alcohols, (b) addition products of 5 to 6 mols of ethylene oxide to 1 mol of dodecylphenol, (0) partial esters of sorbitol with fatty acids having 12 to 18 carbon atoms in a ratio of 1.5 to 3 mols of fatty acid to 1 mol of sorbitol, and (d) mixtures thereof; and (B) utilizing as said aqueous cleaning solution, an aqueous composition containing from 0.05% to 0.5 by weight of an anionic wetting agent and from 0.05% to 0.5% by weight of said oil-soluble, nonionic emulsifier.

2. The process of claim 1 wherein the same oil-soluble, nonionic emulsifier is employed in said cutting, grinding or forming oil based on mineral oil and in said aqueous cleaning solution composition.

3. The process of claim 1 wherein said oil-soluble, nonionic emulsifier is the addition product of 2 mols of ethylene oxide to 1 mol of oleyl alcohol.

4. The process of claim 1 wherein said aqueous cleaning solution composition contains said anionic Wetting agent and said oil-soluble, nonionic emulsifier in a weight ratio of between 4:1 to 1:3 respectively.

References Cited Metal Cleaners; Soap and Sanitary Chemicals; October 1952; pages 4245, 169 and 171 relied on.

MORRIS O. WOLK, Primary Examiner B. S. RICI-IMAN, Assistant Examiner U.S.Cl.X.R. 

